Draw mechanism for straight-bar knitting machines



Feb. 10, 1959 D. MATTHEWS ETAL 2,872,798

DRAW MECHANISM FOR STRAIGHT-BAR KNITTING MACHINES v 19. 1955 5 Sheets-Sheet 1 Filed Dec In ventorJ Attorney:

y. W Fm M 1 D. MATTHEWS ET AL 2, 7

DRAW MECHANISM FOR STRAIGHT-BAR KNITTING MACHINES 5 Sheets-Sheet 2 Filed Dec. 19. 1955 Inventors D. MATTHEWS ETAL 2,872,798

, Feb. 10, 1959 DRAW MECHANISM FOR STRAIGHT-BAR KNITTING MACHINES 5 Sheets-Sheet 3 Filed Dec.

Inventors- Altorney:

D. MATTHEWS ET AL 2,872,798 DRAW MECHANISM FOR STRAIGHT-BAR KNITTING MACHINES Feb. 1Q, 1959 5 Sheets-Sheet 4 Filed Dec.

I n ventorS Attorneys Feb. 10, 1959 D. MATTHEWS ETAL 2,872,798

DRAW MECHANISM FOR STRAIGHT-BAR KNITTING MACHINES 5 Sheets-Sheet 5 Filed Dec.

In ventor:

A Item e y:

Unite States Patent DRAW IVIECHANHSM FOR STRAIGHT- BAR KNITTING MACHINES Application December 19, 1955, Serial No. 554,030

9 'Claims. (Cl. 66-110) This invention relates to improvements in straight-bar knitting machines and refers particularly to the draw mechanism of such machines. In the manufacture of garments or fabric on straight-bar knitting machines it is customary to shape the selvedge edges of the garments or fabric and normally knitting starts at the widest part and continues down to the narrowest part and whilst the number of needles over which knitting takes place is gradually reduced the tie bar which drives the slur cocks continues with its normal motion for knitting on the full width of the needles so that when knitting on less than the full width of the needle bar time is wasted each course whilst the tie bar completes its full movement. The object of the present invention is to provide automatic means for reducing the movement of the tie bar and consequently the movement of the slur cocks as the width of thework is reduced whilst at the same time maintaining the necessary lead of the thread carriers in front of the slur cocks.

According to this invention the thread carrier bar is driven by a flexible member such as a chain or chains which carry a driver to engage with a carrier, bar driving member, the flexible member being reciprocated by a rack moving with the tie bar and means are provided so that the position of the driver relatively to the tie bar is altered each motion of the latter so that the thread carrier bar maintains the required lead over the tie bar. In one arrangement for this purpose oppositely disposed lengths of the flexible member each pass over fixed and movable sprockets, the latter being mounted on a slide which is moved each motion of the tie bar to alter the position of the flexible member and consequently the position of the driver relatively to the tie bar to maintain the lead of the thread carrier bar over the tie bar.

In an alternative arrangement the ends of the flexible member may be connected to a rack which is reciprocated from a rack moving with the tie bar by a pinion disposed between the two racks and means provided to move the pinion relatively to the rack moving with the tie bar between each motion thereof, to adjust the position of the other rack and consequently the position of the driver.

The tie bar is reciprocated by a draw lever which is oscillated by a second lever having a sliding block or blocks thereon which is or are engaged by a pin or pins on a block which is adjustable longitudinally of the draw lever to alter the throw of the draw lever.

The invention will now be more particularly described with reference to the accompanying drawings in which:

Fig. 1 is a front elevation showing one method of adjusting the position of the flexible carrier driving member on each motion of the machine to provide the necessary lead to the carriers over the slur cocks.

Fig. 2 is a front elevation showing the draw mechanism to provide a variable draw.

Fig. 3 is a front elevation showing an alternative method of adjusting the position of the flexible carrier driving member on each motion of the machine.

Fig. 4 is a sectional side elevation of the mechanism shown in Fig. 3 and Fig. 5 is a sectional side elevation of the variable draw mechanism shown in Fig. 2 and also showing the mechanism for withdrawing the tie or slur bar from its operative position during the knitting motions of the machine.

Like numerals indicate like parts throughout the drawings.

In carrying out this invention the thread carrier bar 10 (see Fig. 4) is connected by a latch 11 to a driving member 12 which is reciprocated in well known manner as illustrated in the prior patent of S. A. Monk No. 2,764,007, by a driver 13 (see Figs. 1 and 3) which engages between arms 14, 15 on the driving member 12 and is carried by a flexible member 16 which may conveniently comprise two chains disposed side by side and having the driver 13 disposed between them. The chains also pass in well known manner round sprockets mountedon two saddles 17, 18, the sprockets being arranged on-a fixed bar 18' so that the driver 13 moves into or out of engagement with the arms 14, 15 on the driving member 12 according to the direction in which the driver 13 is moving. The saddles 17, 18 are also movable towards and away from each other to adjust the traverse of the driving member 12 and consequently that of the thread carrier bar 10. The chains forming the flexible member 16 are driven from the tie or slur bar 19 of the machine and in order to reduce the traverse of the tie bar 19 and consequently that of the slur cocks 20 mounted thereon as the width of the work decreases, the tie bar 19 is driven in the following manner.

The tie bar 19 is connected as hereinafter explained to a slide 21 connected to the upper end of a draw lever 22 which is pivoted at its lower end at 23 and is oscillated about its pivot 23 by a second lever 24 which is pivoted at its upper end at 25. This second lever24 may conveniently comprise two parallel arms as shown in Fig. 5 with the draw lever 22 disposed between them, The draw lever 22 carries a block 26 which is adjustable longitudinally of the draw lever and carries pins 27 which engage in openings provided for the purpose in blocks 28 slidably mounted on the arms of the lever 24. The lever 24 is oscillated about its pivot 25 by a cam operated lever 29 which is connected to the arms of the lever 24 by links 30. It will be seen that by adjusting the position of the block 26 on the draw lever 22, the throw of the latter will be altered. In order to adjust the position of the block 26 a screw 31 is provided which passes through the block 26 and is turned to move the block 26 longitudinally of the draw lever 22. In order to tum the screw it is connected through a universal joint 32 with a pinion 33 which is connected by pinions 34, 35, and 36 with a rack 37 which is moved longitudinally as and when required to adjust the position or" the block 26. The rack is moved longitudinally by a lever 38 which is pivoted at 39 and has its lower end connected to the rack 37 and its upper end connected to a box 40 on the narrowing screw 41 so that when the narrowing screw 41 is turned to alter in well known manner the traverse of the thread carriers, the throw of the draw lever 22 is altered at the same time to alter the traverse of the slur cocks. It will therefore be seen that as the traverse of the thread carriers is altered step by step, the traverse of the slur cocks will be correspondingly altered.

The chains which form the flexible member 16 are driven from the draw lever 22 and in one arrangement shown in Fig. lthe chains are endless and the sprockets 45 round which they pass at one end are driven by gears 46, 47, 48 connected between the axle 49 of the sprockets 45 and a rack 50 which is connected to the slide21- and is reciprocated by the draw lever 22. The gear 47 also engages with a rack 51 (see Figs. 2 and 5) on the tie bar 19 so that the latter reciprocates with the chains. For the correct sinking of the yarn on the needles by never/9s the jack sinkers, the thread carriers must traverse with a predetermined lead over the slur cocks and as, in the present arrangement, the chains are driven from the same reciprocating rack 50 which also drives the tie bar 19 provisionmust be made, before each draw motion, to adjust the position of the driver 13 relatively to the tie bar 19 to maintain this lead. For this purpose the upper and lower runs of the chain each pass around two spaced pairs of sprockets 52, 53 and 54, 55 (See Fig. 1) on fixed axles and a pair of intermediate sprockets 56, 57, disposed between each spaced pair. The two pairs of intermediate sprockets 56, 57 are mounted on a slide 58 which is movable transversely of lines joining the centres of each spaced pairs of sprockets. It will therefore be seen that by moving the slide 58 at the appropriate time the position of the driver 13 relatively to the driving sprockets 45 of the chain, and consequently to the tie bar 19 can be altered. In order to alter the position of the slide 58 it is connected by a link 59 to one arm of a bell crank lever 60, the other arm of which is connected to a member 61 which is longitudinally adjusted at the appropriate time by a lever 62 actuated by a cam actuated member 63. The cam 64 to operate the member 63 is preferably driven from the half speed shaft 65 of the machine.

In an alternative arrangement shown in Figs. 3 and 4 the chains which carry the driver 13 are connected to a rack 70 which is reciprocated by a second rack 71 mounted on and moving with the tie bar 19 and driving a pinion 72, the teeth of which engage with the teeth of the other rack 70. It will be seen that the pinion 72 is disposed between the two racks 70, 71 and that by moving the axis of the pinion 72, longitudinally of the racks, the position of the driver 13 relatively to the tie bar 19 can be altered. For this purpose the pinion 72 is mounted on a slide 73 which is connected to a lever 74 moved by a cam actuated member 75, the cam 76 for actuating the member 75 being preferably driven from the half speed shaft 65 of the machine. With either of the arrangements described it will be seen that by moving the cam operated member at the appropriate time, that is between draw motions, the position of the driver 13 relatively to the tie bar 19 can be adjusted so that the thread carriers maintain the necessary lead over the slur cocks and this lead is maintained irrespective of the length of the traverse of the slur cocks.

In order to withdraw the slur cocks 20 from the jacks and into an inoperative position during the knitting motions of the machine, as is necessary when knitting is being carried out on less than the full width of the needle bar, the tie bar 19 on which the slur cocks 20 are mounted is slidingly mounted on a rail 85 carried by the upper ends of arms 77 (see Fig. secured on a shaft 78 which is turned about its axis to withdraw the slur cocks into an inoperative position. The shaft 78 is turned about its axis by arms 79 secured thereto and carrying trucks 80 which ride on cams 81 on the mainshaft 82 of the machine. The earns 81 are shaped so that the slur cocks 20 are withdrawn to an inoperative position after each draw motion and returned to their operative positions before each draw motion. The arms 77 are normally held up to stops 83 by springs 84-.

With a machine constructed as described the lead of the thread carriers over the slur cocks is maintained irrespective of the length of the draw which can be shortened as and when required and the normal speed of the draw retained on a shortened draw by increasing the speed of rotation of the mainshaft by the required amount so that the time required to knit a shaped garment is reduced.

What we claim is:

1. In a straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of chains having a driver carried between them to engage with the driving member, sprockets to carry the chains, a rack to reciprocate the chains, a tie bar connected with the rack, means to reciprocate the rack and means to adjust the position of the driver relatively to the tie bar between successive transversing movements of the latter so that the thread carrier bar maintains the required lead over the tie bar.

2. Ina straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of chains having a driver carried between them to engage with the driving member, sprockets to carry the chains, a rack to reciprocate the chains, a draw lever to reciprocate the rack, a pinion driven by the rack, a second pinion connected therewith and driving a rack secured to a tie bar and means to adjust the position of the driver relatively to the tie bar between successive traversing movements of the latter so that the thread carrier bar maintains the required lead over the tie bar.

3. In a straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of endless chains having a driver carried between them to engage with the driving member, sprockets around which the chains pass at each end arranged to provide upper and lower runs to the chain, a rack connected by gearing to one set of end sprockets, a draw lever to reciprocate the rack, a tie bar driven from the rack, a pair of spaced sprockets in each upper and lower run of the chains, a sprocket disposed between each pair and mounted on a common slide movable transversely of the normal path of the chains and means to move the slide between successive traversing movements of the tie bar to adjust the position of the driver relatively thereto so that the thread carrier bar maintains the required lead over the tie bar.

4. In a straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of chains having a driver carried between them to engage with the driving member, sprockets to carry the chains, a rack, a draw lever to reciprocate the rack, a second rack secured to the chains, a pinion disposed between and forming a driving connection between the racks, a slide movable longitudinally of the racks to carry the pinion, a tie bar, a driving connection between the tie'bar and the first mentioned rack and means to move the slide between successive traversing movements of the tie bar to adjust the position of the driver relatively to the tie bar so that the thread carrier bar maintains the required lead over the tie bar.

5. In a straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of chains having a driver carried between them to engage with the driving member, sprockets to carry the chains, a rack, a driving connection between the rack and the chains, a tie bar connected with the rack, a draw lever to reciprocate the rack, a driving connection between the draw lever and'a cam operated pivoted lever and means to move the driver relatively to the tie bar between successive traversing movements of the latter so that the thread carrier bar maintains the required lead over the tie bar.

6. In a straight-bar knitting machine according to claim 5 said driving connection between the draw lever and cam operated pivoted lever comprising a block movable longitudinally of one lever, means to move the block and a pin on the block engaging in a hole in a member slidable longitudinally of the other lever.

7. In a straight bar knitting machine according to claim 6 said block moving means comprising a screw passing through the block, bearings to support the screw longitudinally of the lever and means to turn the screw.

8. In a straight-bar knitting machine according to claim 5 said cam operated pivoted lever having two parallel arms, a draw lever disposed between the arms, a block movable longitudinally of thedraw lever, a screw disposed longitudinally of the draw lever and passing through the block, pins on the block engaging in holes in members slidably mounted on the arms and means to turn the screw to move the block.

9. In a straight-bar knitting machine the combination of a thread carrier bar, a driving member connected thereto, a pair of chains having a driver carried between them to engage with the driving member, sprockets to carry the chains, a rack to reciprocate the chains, a draw lever connected to the rack, a cam operated pivoted lever, a driving connection between the two levers, means to move the driving connection longitudinally of the levers, a tie bar connected with the rack, slur cocks on the tie bar, arms secured on a shaft to carry the tie bar, means to turn the shaft between motions of the tie bar and means to adjust the position of the driver relatively to the tie bar between successive traversing movements of the latter so that the thread carrier bar maintains the required lead over the tie bar.

References Cited in the file of this patent UNITED STATES PATENTS 

